The current standard pretreatment QA uses film, ion chamber array or diode array to measure the dose distribution of radiation therapy delivery. The pretreatment QA is required for all intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), stereotactic body radiation therapy (SBRT), small field treatment and electron therapy plans. The increasing use of these treatments presents a significant challenge and calls for new tools featuring ease of use, high accuracy, and high spatial and temporal resolutions for dosimetric measurements and QA for standard field size treatment and small field treatment to 5 mm×5 mm.
What is needed is a method of electronic portal imaging (EPID) for radiation dosimetric measurement and QA in radiation therapy having ease of use, high accuracy, and high spatial and temporal resolutions.